Funny you should ask, as since I've been trying to decide if I want to tackle the question on Lincoln being perceived as a bumpkin, I'm actually rereading some of Walter Stahr's Seward: Lincoln's Indispensable Man and it's as good as I remember.

Seward's conduct at the beginning of the administration (when he more or less tried to coopt Lincoln) is better illustrated here than anywhere else, along with a number of other of his controversial actions: throwing people in prison without habeas corpus, the near disaster of the Trent affair, Reconstruction, his work on vastly expanding American territory besides Alaska, and even his 'adoption' of his travel companion/nurse/whatever.

It's also extraordinarily well footnoted and should direct you to pretty much all the other literature out there that references Seward if you want to go further in depth.